Hey everyone,
I have a 95 3vze 4Runner, and I have recently replaced my thermostat. After I took the housing off, put the new thermostat in, and bolted up the housing, I have had a leak ever since then. I put a new O ring on the T-stat, and even replaced the actuall plastic housing. I replaced the housing because I thought that I might not be getting a seal because It possibly had a crack. Still no luck after replacing it.

I have had the t-stat on and off probably half a dozen times, What am I missing? I took it to the dealership to get a recall completed and to see if they could fix it, they wanted to charge me 140$ just to take the timing belt cover off (You can watch the leak come out of the t-stat housing ). When I replaced the t-stat, I also did the waterpump and timing belt and all the hoses. I Know I have a good seal around the water pump. I dont understand what Im missing on the t-stat, any ideas?

 

Sounds like you got some grit on the lip. It's gotta be a lot cleaner than you'd think for it not to leak. When you put it back together this time - you might wanna opt to put some permatex black on there as well.

 

That was actually the last thing I tried to do, Im still getting the leak. Before I put sealent around the housing I had the leak stopped for like three days and then it started again, so I tried putting sealent on it, and it leaked a little worse than before,

 

Hmmm... bummer. Umm, any chance that the thermostat housing itself is dented or gouged?

 

No, I thought thats what the problem might have been so I bought a brand new one. It seems like it might have something to do with the three bolts but I cant figure it out

 

Dang... okay, I'm out of ideas. Hopefully someone else will catch the thread.

 

Thanks though!

 

Take it off and clean it like you've never cleaned it before. I use a die grinder with a scrubby pad. Brake clean the surfaces off, use a good quality sealant like Toyota FIPG or Napa (permatex) "The Right Stuff".

Torque the bolts down to the proper tension if you haven't developed good hand feel. Use some liquid thread sealer on the bolts if the ends of the bolts are exposed to coolant, if they are blind, then use a medium threadlocker. Make sure the bolts have been cleaned on the wire wheel.

Now for the rookie questions. Are you sure it's not the hose? Often the hose can dribble down and look like the stat housing is leaking. Do you have the stat in the correct direction? This shouldn't be too hard to figure out, but post some pictures if are still having problems. Good luck.

 

Thanks wrenchmoster. Im going to give the liquid thread sealer a shot, maybe thats my problem. The water flows out between the housing and the waterpump, right by a bolt so maybe since I havent used any thread sealer, thats where the water is coming from. You can watch where it is leaking, Im still amazed and irritated that the dealership wanted to take my timing belt cover off.
Ill pick up some sealer tomorrow after work, and see if I cant stop it. If not, Ill try to put some pics up to show where the water is coming from.

 

do the bolts on thermastat houseing go through a water jacket

 

sorry that is on a 92 4runner v6

 

check to see if one of the studs backed out when you removed it. Take the housing back off , double nut the stud and see if you can turn the stud in any more. Try that on all three studs to see if any are loosend.

 

Reviving an old thread. Any update on how the issue was fixed?